scott_h
Joined 7 years ago
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11
Member since
Jul 11
Recent submissions
Comment · 2 months ago
Comment · 1 year ago
Interesting stuff, I work with RF and I was curious how a passive component can have such a high gain (given that gain is usually measured as an increase in energy of a signal).
Turns out the way that the gain of a passive reflector seems to be measured is: "the ratio of the power density at a distant point due to the passive repeater to the power density which would exist at the same point" if the repeater were replaced by a matched antenna (or basically nothing at all).
So basically it's a measure of how much better the signal is when you add the reflector, and that's why it can achieve such high gains: because the signals traveling so far are already being atmospherically attenuated by hundreds of dB. Maybe that's not new information to others.
Anyways, cool stuff. Sometimes the best solutions are the simplest.
http://www.gbppr.net/splat/Passive-Repeater-Engineering.pdf#...
Comment · 3 years ago
> So you didn't read the article?
Part of my critique is that the numbers cited in the article don't relate to their meaning. Measuring catalyst by kg instead of kWh is stupid, so $20/kg means jack when you look at what that actually means for a battery. Sounds hard to believe that there is an inexpensive anything made of only things like nickel-molybdenum-cobalt.
> That's all very nice, but that number is from a paper from 2018.
Hey I agree with you, but that's what the article cited. Maybe they shouldn't be citing a 2018 article. And I bet that $83/kWh was absolutely a best case estimate without manufacturing costs, nor accounting for scaling costs. Thats why I added the link for context.
Comment · 3 years ago
Stop posting your own tweets.
Comment · 3 years ago
Guess what component a simulator named diode doesn't have...
Comment · 3 years ago
Guess what component a simulator named diode that doesn't have...
Comment · 5 years ago
Amazingly written!
- Sunstone
- Advanced Assembly
- Sierra Circuits
- Osh Park
They all have ~7 day lead time or shorter. It all comes down to choosing simple processes with generic parts.
Do you have your own machines or just outsource these orders and ensure the supply chain stuff moves along quickly?
I like the idea, more heads in the game makes it cheaper for everyone, but this seems like another hat in the ring.